High burden of blindness at initial hospitalisation with primary angle-closure glaucoma in a national multicentre study in China

Objective To determine the prevalence and risk factors for blindness at initial hospitalisation with primary angle-closure glaucoma (PACG) and proposed glaucoma surgery in China. Methods A multistage stratified sampling method was used to select patients with PACG (1 January 2011 to 31 December 2020) presenting for initial hospitalisation from hospitals of various levels (n=26): 2 nationally leading ophthalmic hospitals, 12 university-affiliated and provincial people's hospitals and 12 city-level hospitals. Blindness is defined according to WHO standards, with visual acuity <3/60 defined as blindness. We used separate logistic regression models to identify the risk factors for blindness in at least one eye and bilateral blindness. Results Among the 3957 patients with PACG included in this study, 42.7% (n=1691) and 5.33% (n=211) had either-eye and bilateral blindness, respectively. In multivariable logistic models, participants with 60-69 years (ORs=1.28, 95% CI 1.06 to 1.55), 70-79 years (OR=2.27, 95% CI 1.85 to 2.78) and >80 years (OR=4.21, 95% CI 3.09 to 5.73) had a higher risk of either-eye blindness compared with those aged 50-59, higher intraocular pressure (IOP; OR=1.06 per mm Hg, 95% CI 1.05 to 1.07), residence in rural areas (OR=1.45, 95% CI 1.24 to 1.70) and presentation to city-level hospitals (vs higher-level facilities, OR=1.53, 95% CI 1.18 to 2.00) increased risk. Similar results were obtained for bilateral blindness. Conclusions In China, two out of every five PACG patients presenting for initial hospitalisation experienced blindness in at least one eye. Efforts to reduce this burden should focus on improving diagnostic and treatment services at city-level facilities in rural settings while focusing on older patients presenting with higher IOP.